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ZL3AI > APRDIG 09.04.03 10:08l 248 Lines 10369 Bytes #999 (0) @ WW
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Subj: TAPR Digest, Apr 06, 2/3
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From: ZL3AI@ZL3VML.#80.NZL.OC
To : APRDIG@WW
Subject: D700 in Mazda Tribute/Ford Escape -- More
From: Ralph Milnes <milnes1@rcn.com>
Date: Sun, 06 Apr 2003 13:19:59 -0400
X-Message-Number: 7
Let me be a little more specific about my antenna quandary...
I intend to garage the car, hence a fixed roof top mount wouldn't seem to
work .. too tall ... and I don't think I want to deal with a fold down. So
I'm thinking of an on-glass antenna or perhaps a hood-lip mount.
73
Ralph
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Subject: Maritime Mobile Weather Stations
From: "Christensen, Eric Harlan" <CHRISTENSENE@MAIL.ECU.EDU>
Date: Sun, 6 Apr 2003 13:31:28 -0400
X-Message-Number: 8
I may be trying to reinvent the wheel here, but I am looking at putting a
weather station on a sailboat (which will be reported to APRS as well) but I
can't figure out how to keep the wind direction correct if the direction of
the base in which the instrument is mounted keeps changing directions.
Anyone have any ideas?
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Subject: Re: D700 in Mazda Tribute/Ford Escape -- More
From: "Wes Johnston" <wes@johnston.net>
Date: Sun, 6 Apr 2003 14:23:01 -0400
X-Message-Number: 9
I've seen glass mount antennas cause too much trouble when running more than
one radio in the car. I'd stay away from glass mount. comet makes an
electric fold down mount however... I have the manual fold down version and
am still waiting for my wife to pull the van into the garage w/o putting it
down. I'm trying to come up with a blinking LED and a mercury switch tied
into the remote garage door opener.
Wes
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Subject: Re: TAPR and APRS at Dayton
From: Stan Horzepa <stanzepa@earthlink.net>
Date: Sun, 06 Apr 2003 14:24:14 -0400
X-Message-Number: 10
TAPR will be at the Hamvention. TAPR will have a booth in a new location
(same building, different spot), the TAPR Forum is scheduled for Friday
morning, and the TAPR Packet Bash is scheduled for Friday night. (Details
will be forthcoming.)
The APRS Forum is scheduled for Friday morning.
Stan, WA1LOU
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Subject: Re: TAPR and APRS at Dayton
From: John Ackermann N8UR <jra@febo.com>
Date: Sun, 06 Apr 2003 14:24:02 -0400
X-Message-Number: 11
TAPR will be at Hamvention as usual... though we'll be in a different space
-- we're moving from two spaces up to three, and consequentely will be a
row over and down a little from the old spot. The new spaces are 607,
608, and 615.
We'll have the BASH Friday evening as usual (look for another message about
that in a couple of days). It'll be same location, same time, same price,
same deal -- order tickets from the office, or on Friday up until about
3:00PM.
The APRS pizza get-together is not TAPR-sponsored, so I don't know whether
that will happen or not.
We'll have the Hamvention page at the website updated soon.
73,
John N8UR
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Subject: FW: Maritime Mobile Weather Stations
From: "Ray McKnight" <shortsheep@worldnet.att.net>
Date: Sun, 6 Apr 2003 11:42:16 -0700
X-Message-Number: 12
First, to make this work, you will have to have input from some sensor,
such as GPS or compass (gyro, flux gate, something that provide the NMEA
output data). This heading data is absolutely essential for calculating
true wind direction. But also keep in mind, if you choose GPS for this,
that most GPS's cannot determine heading unless they are in motion, and
generally traveling above 2 kts. But if there's less than 2 kts of wind,
it's reported as calm anyway. So you're not "sailing" at 2 kts of wind,
and the apparent wind is less important, so it's not much of an issue.
Next, your wind sensor must be able to use the heading data to calculate
true wind. There are very few instruments available that can do that.
Its almost always done externally in software, by comparing apparent
wind data and applying the proper calculations to derive true wind. I
don't know of any APRS software that has this capability. I have some
professional software with this built in, but you certainly wouldn't
want to even consider the complexity of that on a sailboat, unless
you're around the 80-foot category or above, simply because now we're
talking discrete weather data from each sensor, multiple data ports, a
dedicated computer, you get the picture.
If you have onboard navigational instruments, some of the higher end
stuff such as Raytheon and others, can do this calculation for you
easily. It's also usually available in some of the better chart
plotters and radars. The folks that take racing seriously are VERY keen
on accurate wind information. But as you probably know, if you don't
already have good instruments installed, new ones can set you back about
the price of a new car!
Plus you still have the hurdle of how to integrate the NMEA output into
the data being fed to APRS. It can be done fairly easily by combining
NMEA strings from various devices to format a single APRS weather
sentence. Probably a PIC controller would be easy to do. The software I
mentioned that I use can do this: take independent serial or NMEA data
from discrete sensors, parse it, then recombine whatever data segments
you wish to create into a unique, custom NMEA output.
You might also mention how you will be sailing. Offshore, or coastal?
If you're further than about 20 miles, you're probably wasting your time
with APRS since you'll generally be out of range of the majority of land
stations. And they're not enough offshore stations listening to APRS to
be of any use. The ones that do probably already have the weather data
on board that they need anyway, and other than very localized events,
two boats within direct APRS range will have the same basically the same
or very similar weather (since APRS isn't reporting waves and currents
anyway, probably the most useful data for this circumstance).
The most simple method of course you can already do: a manual
calculation of wind vectors using either a calculator or plotting board,
and manually sending a beacon every so often. But I doubt anyone would
do this every 5 minutes or even every 15. It could be useful in certain
situations, say you were sailing with a regatta or race or something.
So to answer you question directly, you probably can't do this easily
with current APRS client software and a laptop.
73's
Ray - WB3ABN
Kingston, WA
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Subject: Re: New Improved Hi-Speed-Keying Version Of Tone-Key
SoundcardInterface Posted
From: "Dick C. Reichenbach" <dreichen@columbus.rr.com>
Date: Sun, 06 Apr 2003 17:21:53 -0400
X-Message-Number: 13
I appreciate the work you have done on this. I was about to put
together your older keyer, but now I'm glad I waited. (ie:
Procrastinated)
It looks like version A is ideal for my Kenwood 261, and version B is
more suited for my Yeasu 1500. Bottom line answer: Do you think that
version B is good enough for 9600 baud packet?
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Subject: Re: Maritime Mobile Weather Stations
From: "Pat Barthelow" <aa6eg@hotmail.com>
Date: Sun, 06 Apr 2003 14:41:05 -0700
X-Message-Number: 14
From: "Christensen, Eric Harlan" <CHRISTENSENE@MAIL.ECU.EDU>
I may be trying to reinvent the wheel here, but I am looking at putting a
weather station on a sailboat (which will be reported to APRS as well) but I
can't figure out how to keep the wind direction correct if the direction of
the base in which the instrument is mounted keeps changing directions.
>
>Anyone have any ideas?
Hmmm...
Great question Eric. Maybe a flux gate compass (electronic; see:
http://www.personal.engin.umich.edu/~johannb/Papers/paper77.pdf with a 0-5
variable DC voltage (I think they are reasonably cheap) representing heading
of the ship, relative to magnetic north. This becomes one input of an op
amp adder circuit, the other input being, the wind vane signal output,
referenced to the direction of the wind relative to the ship, and the
resultant processed voltage could be zeroed and gain adjusted to be zero to
5 volts (hey....maybe zero to 3.60 volts) represents an angle (wind
azimuth) between north and the wind heading. Hmmmm, gotta get out my op
amp books...
Better yet: http://www-s.ti.com/sc/pcsheets/sloa075.pdf shows adder circuits
and op amp circuits, in general.
Btw, another good reference I discovered is:
http://design.stanford.edu/spdl/ME218a/pdffiles
Which are Stanford final exams, with answers, of real application problems
like this.
Good luck, 73,
Pat aa6eg@hotmail.com
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[off topic]
----------------------------------------------------------------------
Subject: Re: New Improved Hi-Speed-Keying Version Of Tone-Key Soundcard...
From: WA8LMF2@aol.com
Date: Sun, 6 Apr 2003 18:39:45 EDT
X-Message-Number: 16
In a message dated 4/6/03 2:22:36 PM Pacific Daylight Time,
dreichen@columbus.rr.com writes:
>I was about to put
>together your older keyer, but now I'm glad I waited. (ie:
>Procrastinated)
>
>It looks like version A is ideal for my Kenwood 261, and version B is
>more suited for my Yeasu 1500. Bottom line answer: Do you think that
>version B is good enough for 9600 baud packet?
Either one will work ( I assume you mean by "Version A" and "Version B" the
two new versions using the op-amp design). Assuming your sound card app and
computer can generate 9600 baud reliably (soundcard timing issues, sample
rates, etc), the interface is going to key the same as with 1200. The same
TX delay (about 3 mS) will apply. Probably the radio's own keyup time and
synthesizer RX-to-TX settling time will introduce far more delay than this
interface does.
Stephen H. Smith wa8lmf @ aol.com
Home Page: http://wa8lmf.com
Ham Radio/Mobile SSTV page: http://members.aol.com/wa8lmf/ham
APRS Stuff
http://members.aol.com/wa8lmf/aprs
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